The sorption of polar and non-polar gases by zeolites

Details of zeolite structures have been obtained by X-ray methods, complete (W. H. Taylor and co-workers 1933-4) in the cases of natrolite, scolecite, mesolite, edingtonite and thomsonite, and partially complete in the cases of chabasite (Wyart 1931, 1933), analcite (Kastner 1931; Taylor 1930) and heulandite (Parsons 1932; Wyart 1933). Three types of zeolite framework have been recognized: A. Three dimentional networks (chabasite, analcite). B. Fibre structures (natrolite, scolecite, thomsonite, mesolite, edingtonite). C. Plate-like structures (heulandite, and possibly mesolite). These frameworks are anionic Si-O-Al networks, containing interstitial and exchangeable cations, and also neutral molecules of water, which are replaceable in some instances by molecules of ammonia, iodine, mercury or gases.